Pressure sensitive adhesive tape having release coating of composition of aldehyde or imide resin, sulphated or sulphonated wetting agent, and reaction product of monoene or diene monomers and carboxylic acid



Dec. 4, 1962 w. c. DABRosKx 3,067,057

PRESSURE sENsITIvE ADHESIVE TAPE HAvINGRELEAsE coAIING oF coMPosITIoN oF ALDEHYDE 0R IMIDE RESIN, SULRHATED oR SULPHONATED WETTING AGENT, AND REACTION PRODUCT OF MONOENE OR DIENE MONOMERS AND CARBOXYLIC ACID Filed oct. 2e, 1959 ATTORNEY Unite States Patent Ohce 3,067,657 Patented Dec. 4, 1962 3,067,057 PRESSURE SENSITIVE ADHESIVE TAPE HAVING RELEASE CATENG F COMPOSHION 0F AL- DEHYDE 0R HMDE RESEN, SULPHATED 0R SULPHNATED WETTING AGENT, AND RE- AUHN PRDUCT GF MQN'UENE 0R DENE MNMERS AND CARBXYMC AUD Winifred Christina Dahroski, East Brunswick, NJ., as-

signer to Johnson & Johnson, a corporation of New Jersey Filed (ict. 26, 1959, Ser. No. 848,560 9 Ciaims. (Cl. E17-63.5)

This invention relates to the art of release coatings, and m-ore particularly to a release coating containing a mixture of a water-dispersible, heat-reactive aldehyde or imide resin, an emulsifying agent comprising a sulfated or sulfonated wetting agent, and an oil-resistant film-forming polymer derived from a polymeric reaction product of one or more monoene or diene monomers and a monomeric, polymerizable carboxylic acid or anhydride, with a double bond a, to the carboxylic group. It also relates to pressure-sensitive adhesive tapes having such release coatings, and the method of making such pressure-sensitive adhesive tapes.

The term backingj as used herein, means any suitable material for supporting a pressure-sensitive adhesive.

The term pressure-sensitive adhesive, as used herein, means an elastomeric material, such as a natural or synthetic rubber, with or Without a resinous component, which provides a normally aggressively tacky pressuresensitive adhesive that can be applied with light finger pressure in the absence of heat and solvent.

rihe term release coating, as used herein, means a thin coating applied to the opposite side of the backing from the side which carries the pressure-sensitive adhesive, or to a liner, to permit easy unwinding after being rolled or stacked with the release material in contact with the pressure-sensitive adhesive of a super-imposed layer of tape or a label.

Pressure-sensitive tapes are usually wound in rolls, thus bringing the backing in one layer into contact with the pressure-sensitive adhesive coating on the layer thereabove. rhis has a tendency to cause the upper layer to adhere to the next lower layer, making it difficult to unwind the tape because of the aggressively tacky character of the pressure-sensitive adhesive.

Release coatings are therefore usually applied to the backing of pressure-sensitive tapes in order to permit easy unwinding of the tape, without detackifying the pressuresensitive adhesive coating or splitting the backing.

Numerous attempts have been made to overcome these disadvantages, but many prior release coatings have been objectionable for various reas-ons. One very important reason is that after aging, especially at elevated temperatures, many release coatings lose their release properties. ln other words, the release feature is fugitive. Examples of such release agents are paratiin wax coatings or emulsions.

Another objectionable feature in s-ome prior art release coatings is that they lose their adhesiveness to the backing material and become detached therefrom, becoming attached to the pressure-sensitive side of the tape, and thereby lessening its adhesive characteristics, usually referred to as detackication A further objection to some prior release coatings is inadequate heat stability and solvent resistance.

Most release agents do not print and it is usually difcult to unwind most of those that will print because the ink has blocked the action of the release agent. This is particularly true where the printing covers a major part of the surface of the backing. By the present invention, this ditliculty is avoided, apparently because the release agent migrates through the ink and still gives release.

I have discovered that these and other disadvantages 0f prior art release coatings can be overcome, and pressure-sensitive adhesive tape obtained which will have good release characteristics and will not lose its release properties on aging, and to which ink will adhere', by applying to the opposite side of the backing a thin coating of a mixture of a water-dispersible, heat-reactive aldehyde or imide resin, an emulsifying agent comprising a sulfated or sulfonated wetting agent containing atleast one aliphatic straight chain of 11-21 carbon atoms, and an oil-resistant, film-forming polymer derived from a polymeric reaction product of one or more monoene and/or diene monomers and a monomeric polymerizable carboxylic acid or anhydride, with a double bond a, to the carboxylic group.

It is therefore an object of this invention to provide a new and useful class of release coatings.

vIt is another object to provide pressure-sensitive tapes containing a normally aggressively tacky pressure-sensitive adhesive on one side and a thin release coating on the opposite side, which will permit easy unwinding of the tape and not detackify the pressure-sensitive adhesive, nor be offset from the backing to the pressure-sensitive adhesive immediately thereabove.

It is also an object to provide a release coating which will have good ink adherence.

It is a further object to provide a method of making pressure-sensitive adhesive tapes which maintain effective release characteristics on aging for long periods of time, and to which ink will continue to anchor, even though subjected to elevated temperatures.

lt is another object to eliminate multiple backsize or release coatings.

With the above and other objects in view, which will be apparent as the description proceeds, I have set forth my invention in the following specification and have illustrated certain embodiments thereof in the following examples, and the accompanying drawing but it will be understood that this disclosure is merely for the purpose of illustrating practical embodiments of the invention, and the latter is not to be limited thereto.

SATURATED BACKINGS Any of the conventional backings for pressure-senstive tape can be used with this invention. One of the most widely used backings is kraft paper, such as 27-pound or Sti-pound crepe paper. Another widely used type of paper is made from rope or hemp. A typical example is Flexrope, which is a rope paper supplied by the I. A. Manning Co. Suitable film backings are cellulose acetate, cellophane, cellulose acetate-butyrate, cellulose propionate, vinyl chloride or polyethylene terephthalate.

Paper backings are generally saturated with a rubber compound to give strength and improve the delamination resistance. These saturants may vary widely, but suitable examples are as follows:

Saturated Backing 1 30# kraft crepe paper was saturated with an amount (dry weight) of the following saturant equal to of the Weight of the unsattlrated kraft, and cured at 380 F. for 1 minute.

Parts by weight of total solids Copolymer of butadiene-acrylonitrile (67:33)

(40% solids) 70.0 Copolymer of butadiene-styrene (50:50)

(40% solids) 17.5 Copolymer of butadiene-styrene (:85)

(42% solids) 10.0 Water-dispersible, heat-reactive phenolformaldehyde resin (65% solids) 2.0

Tetra sodium salt of ethylene-diamine tetra acetic acid solids) .5 Water to desired solids.

Saturated Backing Z 4 mils Flexrope was saturated with an amount (dry Weight) of the rollo-wing saturant equal to 85% of the Weight of the unsaturated Flexrope.

Parts by Weight of total solids Copolymer of butadiene-acrylonitrile (67:33)

(40% solids) 55.0 Copolymer of butadiene-stryene (50:50)

(40% solids) 25.0 Copolymer of butadiene-stryene (15:85)

v (42% solids) 19.5

Tetra sodium salt of ethylene-diamine tetra acetic acid (30% solids) .5 Water to desired solids. i Y

Copolymer of butadiene-acrylonitrile (67:33)

(40% solids) 61.0 Copolyrner of butadiene-styrene (50:50)

(40%Y solids) 26.0 Titanium dioxide dispersion (59% solids) 13.0

Tetra sodiumv salt of ethylene-diamine tetra acetic acid (30% solids) .4 Aminox (antioxidant) (diphenylamine acetone reaction product) (Naugatuck Chemical Co.) Water to desired solids.

Saturated Backing 4 4 mils Flexrope Was saturated with an amount (dry Weight) of the following saturant equal to 85% of the weight of the unsaturated Flexrope.

Parts by Weight of total solids Copolymer of butadiene-acrylonitrile (67:33)

(40% solids) 43.0 Copolymer of butadiene-styrene (50:50)

(38.5% solids) 18.0 Titanium dioxide dispersion (59% solids) 6.0

Tetra sodium salt of ethylene-diamine tetra acetic acid (30% solids) .3 Aminox (antioxidant) (diphenylamine acetone reaction product) (Naugatuck Chemical Co.) .005 Water to desired solids.

4 ADHESWE A large Variety of adhesive masses may be-used to impart the aggressively tacky adhesive properties. Examples of suitable adhesive masses are as follows:

Adhesive A Parts by Weight Copolymer of butadiene-styrene (77:23) 31 Crude rubber 43 Pure gum reclaim (76% rubber hydrocarbons) 12.V Zinc oxide 50 2,5-ditertiary amyl hydroquinone 1 2,6-ditertiary butyl 4-methyl phenol 1 Phenolated polyterpene resin (14% phenol) 57 Tetra ethylene pentamine l Triphenyl phosphite 5 Adhesive B Copolymer of butadiene-styrene (77:23) 3l Crude rubber 43 Pure gum reclaim (76% rubber hydrocarbons) l2 Zinc oxide 50 2,5-ditertiary amyl hydroquinone 1 2,6-ditertiary butyl 4-methyl phenol 1 Pure polyterpene hydrocarbon resin (NLP.

70 C.) 57 Triphenyl phosphite 7 Hydrocarbons of high molecular Weight derived entirely from selected crude petroleum 6 Lecithin- V v .5

208.5 Adhesive C Crude rubber 60 Aluminum hydrate 21.5 Titanium dioxide 7- Pure polyterpene hydrocarbon resin (MP. 115

C.) 50 M-tolylene diisocyanate 1 2,5-ditertiary amyl hydroquinone 1 2,6-ditertiary butyl 4-methyl phenol 1 Lecithin 4 Tetra sodium salt of ethylene-diamine tetra acetic acid 1 146.5 Adhesive D Copolymer of butadiene-styrene (77:23) 33 Crude rubber 33 Zinc oxide 36 2,5-ditertiary amyl hydroquinone 1.5 2,6-ditertiary butyl 4-methyl phenol 1.5 Heat-hardening p-octyl phenol-formaldehyde resinV (MP. C.) 13 Diethylene glycol ester of disproportionated rosin 7l Tetra sodium salt of ethylene-diamine tetra acetic acid 1 190.0 Adhesive E Crude rubber 71 Aluminum hydrate 34 Pure polyterpene hydrocarbon resin (MP.

C.) 33.5 2,5-ditertiary amyl hydroquinone 1.8 Nonreactive octyl phenol-formaldehyde resin (M.P. 90 C.) 8 Triphenyl phosphite 3.5 Lecithin 4.5

Adhesive F Parts by weight Nonreactive rosin modified phenol-formaldehyde resin (Amberol M-SS, made by Rohm & Haas) (MP. 14S-155 C.) 7

under this trade name by the American Cyanamid Company, and is believed to be a mixture of approximately 100 parts of 63% ethyl acrylate, 35% acrylonitrile and 2% methacrylic acid, and

4.5 parts of Duponol C (sodium lauryl sulfate), (sold by E. I. du Pont de Nemours & Co.)

100 parts of Cypel resin emulsion (40% solids) are mixed with 10 parts of a Water-dispersible, heat-reactive phenol-formaldehyde (65% solids).

EXAMPLE Ia Backsize I is applied to saturated paper 1 at 0.3 oz./sq. yd. (dry Weight), and cured at 300 F. for 1 minute. Adhesive A is applied to the opposite side at 2.5 02./ sq. yd. (dry weight).

EXAMPLE Ib Backsize I is applied to saturated paper 1 at 0.3 oz./sq. yd. (dry Weight), and cured at 300 F. for 1 minute. Adhesive B is coated on the opposite side at 2.35 oz./sq. yd. (dry Weight).

EXAMPLE Ic Backsize I is applied to saturated paper 1 at 0.3 oz./ sq. yd. (dry Weight), and cured at 300 F. for 1 minute. Ad-

M-tolylene diisocyanate 2 hesive C is coated on the opposite side at 2.25 02./ sq. yd. 2,5-ditertiary amyl hydroquinone 1.2 (dry Weight). 2,6-ditertiary butyl 4-methy1 phenol 1.2 EXAWPLE Id Backsize I is applied to saturated paper 1 at 0.3 oz./sq. 163-4 30 yd. (dry Weight. Adhesive D is applied on the opposite Adheswe H side at 1.8 oz./sq. yd. (dry weight), and both the adhesive Crude rubber and backsize cured at 320 F. for 1 minute. Aluminum hydrate 165 Release and tack results with the tapes of Examples Titanium dioxide 12 Ia-1d made by test procedures 1 and A, respectively, are Pure polyterpene hydrocarbon resin (M P. 115 35 as OHOWS:

C. 43 2,5-ditertiary amyl hydroquinone 1.5 Adhesion Nonreactive rosin modified phenol-formaldehyde Examl t9 fwk- Tack resin (Amberol ivi-ss) (M P. 14s-155 C.) 7 me Triphenyl phosphite 3 40 Tn 22 2O Lecithin 4 1b "M :I 2o f2.3 Ic 12 .1s 147.0 I 16 20 Adhesive J The test procedure used for evaluating the release Cfude ubber 500 4.5 agents in Examples I to V, inclusive, and XI through Zmc OXlde i r; 290 XIII, is as follows: Pupolyterpene hydrocarbon resin (M.P. 115 49 0 RELEASE PROCEDURE 1 M-tolylene diisocyanate 2.5 After aging the roll or" coated tape for 7 days at room Pure polyterpene hydrocarbon resin (MP. 70 50 temperature, the adhesion of the tape to its own backing C. 15.0 as it is unvvound on a roll is measured by placing the roll Butyl phenol-formaldehyde resin (MP. 121-138 of tape on a freerturning core-sized spindle and pulling the C.) 3.0` tape Over a series of rolls at a constant speed or 150 feet 2,5-ditertiary amyl hydroquinone 1.0 per minute. The resistance of the roll of tape to this un- Tetra sodium salt of ethylene-diamine tetra acetic Wind force is measured in ounces and recorded on a chart acid 4.25 in ounces per inch width. 2,6-dlt61'la1y butyl pafaCfeSOl TACK PROCEDURE A Lecithin 2.0 i

This test 1s a measure of quick-stick or instantane- 15725 60 ous grab. A piece of tape, adhesive mass side up, is

RELEASE BAcKsrzE The Cypel resin emulsion used in this and some of the other backsizes of this invention is a product sold placed on the level portion of a channeled metal strip which has at one end a curved elevation based on a 12 radius. A 1" diameter clean steel ball is dropped from a measured height and rolls down the slope onto the tape. The distance the ball rolls before coming to a stop is recorded, and results are reported in height dropped divided by the distance travelled.

Backsze 1I Parts by Wet Weight Cypel resin emulsion (40% solids) 100 Water-dispersible, heat-reactive urea-formaldehyde resin (30% solids) 3 parts of Cypel resin emulsion (40% solids) are mixed with 3 parts of a Water-dispersible, heat-reactive urea-formaldehyde resin (30% solids).

V s EXAM-PLE 1ra Backsize II is applied to saturated backing 3 at about .25 oz./sq. yd. (dry weight), and cured at 300 F. for 1 minute. Adhesive F is coated on the opposite side at 1.6 oz./sq. yd. (dry weight).

EXAMPLE Hb lBacksiZe II is applied to Saturated backing 2 at about .25 oz./sq. yd. (dry weight), and cured at 300 F. for 1 minute. Adhesive E is coated on the opposite side at 1.6 oz./sq. yd. (dry weight).

EXAMPLE Irc 'Backsize II is applied to saturated backing 4 at about .25 oz./sq. yd. (dry weight), and cured at 300 F. for 1 minute. Adhesive C is coated on the opposite side at 1.8 oz./sq. yd. (dry weight).

EXAMPLE IId Backsize II is applied to saturated backing 3 at about .25 oz./sq. yd. (dry weight). Adhesive D is coated on the opposite side at 1.2 oz./ sq. yd. (dry weight) and both the adhesive and backsize are cured at 320 F. for 1 minute.

EXAMPLE IIe yBacksize II is applied to saturated backinfz.7 3 at about .25 oz./sq. yd. (dry Weight), and cured at 300 F. for 1 minute. Adhesive H is coated on the opposite side at 1.6 oz./sq. yd. (dry weight).

Release and tack results with the tapes of Examples IIa-IIe made by test procedures 1 and A, respectively, are as follows:

Adhesion Example to Back- Tack ing, oz.

Ha 8 6.Y IIb 20 1. 0 lic. 10 17 r Hd 8 27 He 1i 36 Bac/:size III Parts by wet weight Cypel resin emulsion (40% solids) 100 Water-dispersible, heat-reactive phenol-formaldehyde -resin (65% solids) 20 100 parts of Cypel resin emulsion (40% solids) are mixed with parts of a Water-dispersible, heat-reactive phenol-formaldehyde resin (65% solids).

EXAMPLE III Adhesion to backing oz-- 22 Tack .16v

Backsze IV :Parts by wet weight Cypel resin emulsion (40% solids) 100 Water-dispersible, heat-reactive phenol-formaldehyde resin (65% solids) 30 100 parts of Cypel resin emulsion (40% solids) are mixed with parts of a water-dispersible, heat-reactive phenol-formaldehyde resin (65% solids).

EXAMPLE IV ABacksize IV is applied to saturated paper 1 at 0.3 oz./sq. yd. (dry weight), and cured at 300 F. for 1 minute. Adhesive G is coated on the opposite side at 2.25 02./ sq. yd. (dry weight).

Release and tack results with this tape, using adhesive G, made by test procedures 1 and A, respectively, are as follows:

Adhesion to backing, w Qz 36 Tack .20

Backsze V Parts by wet weight Cypel resin emulsion (40% solids) 100 Water-dispersible, heat-reactive urea-formaldehyde resin (30% solids) 10 parts of Cypel resin emulsion (40% solids) are mixed with l0 parts of a water-dispersible, heat-reactive urea-formaldehyde resin (30% solids).

EXAMPLE V Adhesion to backing oz 22 Tack .25

Backsze Vl Parts by wet weight Emulsion interpolymer ofv 63% ethyl` acrylate, 35

acrylonitrile, 3% methacrylic acid emulsied withl 4.5 parts of Duponol C (sodium lauryl sulfate) 100 Water-dispersible, heat-reactive phenol-formaldehyde resin (65%` solids) 10 PROCEDURE FOR PREPARATION oF THE EMULsroNv FOR EXAMPLES VI-VH AND XIV 4.5 p arts of Duponol C are added to 100 parts of ion exchanged water which contains 0.75 part of sodium bicarbonate. The mixture is placed in a reaction flask provi-ded with stirrer, reflux condenser, thermometer, two addition funnels and a bubble tube for introducing nitrogen. Nitrogen is started bubbling through and the tiask is heated to 86v C. A catalyst solution (0.7 partr arnmonium persulfate, 0.19 part sodium bicarbonate and 25 parts water) and a mixture of the 3 monomers (63 parts ethyl acrylate, 35 parts acrylonitrile and 3 parts methacrylic acid) is added 4dropwise at such a rate that all of the monomer solution and "/s of the catalyst solution are introduced within a period of 21/2 hours. The remaining 1/5 of the catalyst solution is added within a further 1/2 hour period. Temperature is kept at 86 C. during the 3 hours reaction time. Steam distillation is then carried out for 1 hour to remove unreacted monomer. A polymer solution of Ztl-25% solids is obtained.

100 parts of this interpolymer-Duponol C compositionV Room Temner- F.

attire Adhesion to Backing. oun ces.. 0 i 0 Tack grarns. 500 I 500 The test procedure used for evaluating the release agent in Backsizes VI to VIII and XIV is as follows:

RELEASE PROCEDURE 2 (1) Knife-coat the backsize being tested onto a 2 mil cellulose acetate iilm at a dry coating weight of approximately 0.04 oz./sq. yd. This coating is then cured at 300 F. for l minute.

(2) Apply the adhesive side of a 1 inch wide standard test tape to the backsized side of the cellulose acetate film. The standard test tape is composed of a saturated backing 1 which is coated with 2.35 oz./sq. yd. of adhesive I.

(3) Place 4 strips in Carver Laboratory press (without heat) and apply 2750 pounds pressure for 15 minutes. Since the platen is 6 inches square, With four strips of tape the pressure is 114 pounds per square inch.

(4) Condition overnight at 72 F., 50% relative humidity, herein referred to as room temperature test. Other samples are conditioned 24 hours at 120 F. and then cooled to room temperature for further testing. These samples are referred to as 120 F. tests.

(5) Attach free end of tape to spring balance mounted horizontally and having a maximum indicator.

(6) Holding the tape-backing assembly so that the tape is pulled oi at a 180 angle, pull the hacking from the tape as rapidly as possible without jerking.

(7) Record the maximum value indicated in ounces.

(8) Place the stripped tape lightly back 'on the same surface from which it was removed and save for 4tack tests.

The procedure for preparing the sample and measuring tackiness in Backsizes VI to VII and XIV to XXIII is as follows:

TACK PROCEDURE B (l) `Cut sample of tape to be tested 6 inches long and 1/2 inch wide. g

(2) Wrap tape around plastic ring with the adhesive mass side out and secure by overlapping the ends of the tape. Tape should iit snugly around the ring but should not be tight enough to distort the ring. Do not touch that portion of the mass which will come in contact with the pendulum.

(3) Secure the plastic ring lto the end of the horizontal arm which actuates the spring balance.

(4) Clean the stainless steel contact surface on the pendulum with methyl ethyl ketone.

(5) Swing the pendulum to its highest position opposite the sample and secure it with the catclL (6) Release the catch on the pendulum so that the pendulum swings down and up, contacting the tape on the ring. In swinging back, the pendulum will pull the ring and the horizontal arm and will thereby depress the spring balance an amount related to the tackiness of the tape.

(7) Record the maximum reading on the spring balance.

The machine for measuring tack is a pendulnmtype instrument in which a pendulum, with a polished flat stainless steel surface at its outer extremity, swings approximately 145, lightly contacting the adhesive surface of the tape which is wrapped, adhesive side out, around a ring-made from 5 mil cellulose acetate. The acetate ring, which is 1%. inches in diameter and 1/2 inch wide, is mounted near the free end of a horizontal arm pivoted at the same point as the pendulum and the free end rests on a spring balance which measures the vertical deection of the horizontal arm. Therefore, as the pendulum starts to swing hack after contacting the adhesive, it draws down the horizontal arm and deiects the spring balance an amount related to the tackiness of the tape.

Backsze VII Parts by wet weight Emulsion interpolymer of 63% ethyl acrylate, 35% acrylonitrile, 3% methacrylic acid emulsified with 4.5 parts of Duponol C (sodium lauryl sulfate) 100 Water dispersible, heat reactive urea -formaldehyde resin (30% solids) 3 This emulsion is prepared by using the procedure employed in making the emulsion for Backsize VI.

parts of this interpolymer-Duponol C composition are mixed with 3 parts of water dispersible, heat reactive urea-formaldehyde resin (30% solids).

EXAMPLE VII Backsize VII was evaluated for release and tack results by test procedures 2 and B, respectively, with the following results:

Room Temperatuic Adhesion to Backing -ounces.- 0 0 Tack grams. 320 300 Backsz'ze VIII Parts by wet weight Emulsion interpolymer of 57% ethyl acrylate, 40% acrylonitrile, 3% methacrylic acid emulsied with 4.5 parts of Duponol C (sodium lauryl sulfate) 100 Water-dispersible, heat-reactive phenol-formaldehyde resin (65% solids) 10 This emulsion is prepared by using the procedure employed in making the emulsion for Backsize VI.

100 parts of this interpolymer-Duponol C composition are mixed with 10 parts of water-dispersible, heat-reactive phenol-formaldehyde resin (65 solids).

EXAMPLE VIII A Backsize VIII was evaluated for release and tack results by test procedures 2 and B, respectively, with the following results:

Room Temperature Adhesion to Backing .ounees. Tack grams Backsize IX 5 aqueous solution of Backsize I.

EXAMPLE IX Adhesion to backing oz-- Tack Backsize X Parts by wet weight Resyn emulsion 25-2203 (50% solids) 100 Duponol C (sodium lauryl sulfate) (25% solids) 10 Water-dispersible, heat-reactive phenol-formaldehyde resin (65% solids) 10 Resyn 25-2203 is believed to be an interpolymer of 67% polyvinyl acetate 30% ethyl acrylate 3% acrylic acid sold by National Starch Co.

100 parts of Resyn emulsion (50% solids) are mixed with 10 parts of Duponol C and l0 parts of a waterdispersible, heat-reactive phenol-formaldehyde resin (65% solids).

EXAMBLE X Backsize X is coated on saturated backing 1 at 0.3

oz./sq. yd. (dry weight), and cured at 300 F. for 1 min-' ute. Adhesive C is applied to the opposite `side at 2.25 oz./sq. yd. (dry weight).

Release and tack results of this tape, made by test procedures 1 and A, respectively, are as follows:

Adhension to backing oz. 6 Tack .25

Backsze XI Parts by Wet weight Carboxy-modied acrylonitrilebutadiene (42% solids) (Nitrex 2615) 100 Duponol C (sodium lauryl sulfateV (25% solids) 10 Kymene 55'7 resin (vinyl phthalimide resin) (10% solids) 4 The carboxy-modified acrylonitrile-butadiene is sold by Naugatuck Chemical Co., andV is believed to be a polymer of an acrylic acid, acrylonitrile and butadiene.

The K3/mene 557 resin is sold by Hercules Powder Co. and is believed to be vinyl phthalimide resin.

The above ingredients are mixed together untilhomogeneous.

EXAMPLE XI Backsize XI is coatedv on saturated backing 1 at 0.3 oz./sq. yd. (dry weight), and cured at 300 F. for 1 minute. Adhesive G is coated on the opposite side at 2.25l

oz./Sq. yd. (dry Weight).

Release and tack results of this tape, made by test procedures 1' andA, respectively, are as follows:

Adhesion to backing oz. 7 Tack .23

Backsize Xll Parts by wet weight Resyn emulsion 25-2203 (50%V solids) 100- Duponol C (sodium lauryl sulfate) (25% solids) 10 Water-dispersible, heat-reactive phenol-formaldehyde resin (65% solids) l0 The above ingredientsl are mixed together until homogeneous.

EXAMPLE XII Backsize XII is. coated on saturated backing l at 0.3 oz./ sq. yd. (dry Weight), and cured at 300 F. for l minute. Adhesive Gis coated on the opposite side at 2.25 oz/sq. yd. (dry weight).

Release and tack results of this tape, made by test procedures 1 and A, respectively, are as follows:

Adhesion to 'backing oz. 6 Tack .25

Backsz'ze XIII Parts by Wet weight Rhoplex emulsion B-l 100 Duponol C (sodium lauryl sulfate) (25% solids) l0 Water-dispersible, heat-reactive phenol-formaldehyde resin (65% solids) l0 Sineplex emulsion B-lS is sold by Rohm and Haas Co., and is believed to be an interpolymer emulsion of 65% ethyl acrylate, 30% methyl methacrylate and 5% acrylic acid.

The above ingredientsV are mixed together until homogeneous.

EXAMPLE XIII Backsize XII is coated on saturated backing 1 at 0.3 oz./sq. yd. (dry Weight), and cured at 300 F. for l minute. Adlesive G was coated on the opposite side at 2.25 til/sq. yid. (dry weight).

Release and tack results of this tape, made by testY procedures l and A, respectivel are as follows:

Adhesion to backing oz. 9 Tack .26

Backsize XIV Parts by wet weight Emulsion interpolymer solids) of 60% ethyl acrylate, 35%acrylonitrile, 5% methacrylic acid emulsiiied with 4.5 parts of Dresinate 731 (sodium salt of disproportionated rosin acids) (sold by Hercules Powder Co.) 100 Water-dispersible, heat-reactive phenol-formaldehyde resin (657 solids) 5 This emulsion is prepared by using the procedure employed in making the emulsion for Backsize VI.

100 parts of this interpolymer-Dresinate composition are mixed with 5 parts of Water-dispersible, heat-reactive 1. phenol-formaldehyderesin (65% solids).

EXAMPLE XIV V Release and tack results of this backsize, made by test procedures 2 and A, respectively, are as follows:

Room Temie- 120 F.

ature Adhesion to Backing ounces.- 32 28 Tack 0.4 oss This backsize was used as a control to show that Dresinate 731 was not a -suitable emulsifying agent for the purpose of this invention.

Backsze XV Parts by wet weight The emulsion of Backsize XIV Water-dispersible, heat-reactive phenol-formaldehyde resin (65% solids) 5 Igepon 'TC-42 (N-coco arylN-methyl taurine, sodium salt) (24.8% solids) (sold by Antara Chemical Division of General Aniline & Film Co.) 4.0

This. emulsion ispreparedby using the procedure employed in making the emulsionfor Backsize XlV.

EXAMPLE XV The procedure of Example XV is followed, except Y that Backsize XV -is used instead of Backsize XIV.

Release and tack results of this backsize, made. by test procedures 2 and A, respectively, are as follows:

hyde resin (65% solids) 5 Igepon AC-78 (coconut acid ester of sodium isethionate,-HOCH2CH2SO3-M) (85% solids) (sold by Antara Chemical) 1.2

This emulsion is prepared by using the procedure employed in making the emulsion for Backsize XlV.

EXAMPLE XVI The procedure of Example XIV is followed, except that Backsize XV-I is used instead of Eacksize XIV.

13 Release and tack results of this backsize, made by test procedures 2 and A, respectively, are as follows:

Room Temperature Adhesion to Backing .ounces.. 0 Tack Release and tack results of this backsize, made by test procedures 2 and A, respectively, are as follows:

Room Temperature Adhesion to Backing ounces.. 0 12 Tack 0. 36 l). 44

Backsze XVIII Parts by wet weight T he emulsion of Backsize XIV 100` Water-dispersible, heat-reactive phenol-formaldehycle resin (65% solids) 5 Ultrawet K (sodium dodecyl benzene sulfonate) (75% solids) (sold by Atlantic Chemical Co.) 1.3

ri`his emulsion is prepared by using the procedure ernployed in making the emulsion for Backsize XIV.

EXAMPLE XVIII The procedure of Example XIV is followed, except that Backsize XVIII is used instead of Backsize XIV.

Release and tack results of this backsize, made by test procedures 2 and A, respectively, are as follows:

Room Te1nperazure Adhesion to Backing ounces.. 0 0 Tack 0. i4

Backsze XIX Parts `by Wet weight I e emulsion of Baoksize XIV 100 Water-dispersible, heat reactive phenol-formaldehyde resin (65% solids) 5 Triton X-ZOS (octyl phenoxy diethylene-oxyethyl sulfonate, sediurn salt) (i6.3% solids) (sold by Rohm 81 Haas) This emulsion is prepared by using the procedure employed in making the emulsion for Backsize XIV.

Although the chain attached to the sulfonate radical in Triton X-200 is not strictly a straight chain hydrocarbon radical, it has a long term structure similar to a straight chain radical and has no polar substituents, hence it functions in the sante manner, and in this application it should be considered an equivalent to the straight chain radical.

14 EXAMPLE XIX The procedure of Example XIV is followed, except that Backsize XIX is used instead of Backsize IV.

Release and tack results of this backsize, made by test rocedures 2 and A, respectively, are as follows:

Room 'Ie'nlpei- 120 F.

attire Adhesion to Backing ounces.. 3 10 Tack 0. 65 0.33

Backsz'ze XX Parts by wet weight The emulsion of Backsize XIV Water-dispersible, heat-reactive phenol-formaldehyde resin (65% solids) 5 Sipon ES (lauryl ether of triethylene glycol sulfate, sodium salt) (26.5% solids) (sold by American Alcolao Corp.) 3.7

rl`l1is emulsion is prepared by using the procedure ernployed in making the emulsion for Backsize XIV.

EXAMPLE XX The procedure of Example XIV is followed, except that Backsize XX is used instead of Backsize XIV.

Release and tack results of this backsize, made Yby test procedures 2 and A, respectively, are as follows:

Room Temper- F ature Adhesion to Backing ounces 0 0. Tack 0.44 0.33

Backsz'ze XXI Parts by wet weight The emulsion of Baciisize XIV 100 Water-dispersible, heat-reactive phenol-formaldehyde resin (65% solids) 5 Aerosol 22 (tetra sodium N-(1,2 dicarboxyethyl) N octadecylsulfosuccinirnate) (35% solids) (sold by American Cyanarnid Co.) 2.9

This emulsion is prepared by using the procedure employed in making the emulsion for Backsize XIV.

EXAMPLE XXI The procedure of Example XIV is followed, except that Backsize XXI is used instead of Backsize XIV.

Reiease and tack results of this backsize, made `by test procedures 2 and A, respectively, are as follows:

Room Temper- 12 F.

ature Adhesion to Backing ounces 6 12 Tack: 0. 5T 0. 4

Backsz'ze XXII Parts by wet weight The emulsion of Backsize XIV 100 Water-dispersible, heat-reactive phenol-formalde hyde resin (65% solids) 5 Aerosol 18 (disodiurn N-oetadecyl sulfosuccinirnate) (35% solids) (sold by American Cyanarnid Co.) 2.9

This emulsion is prepared by using the procedure ernpioyed in making the emulsion for Backsize XIV.

EXAMPLE XXII The procedure of Example XIV is followed, except that Backsize XXII is used instead of Backsize XIV.

Release and tack results of this backsize, made by test procedures 2 and A, res ectively, are as follows:

Room Temper- 12()L7 l?.

ature Adhesion to Baclrirny .ounccs. 0 G. 4 0. 3

Additional examples of suitable release backsizes, using different polymerizable carboxylic acid-containing moncmers, are as follows:

Backsize XXIII This backsize and Backsizes XXIV-XXV I may be prepared and used as described in the previous examples, in the making of release coatings and pressure-sensitive adhesive tapes, with comparable results.

Backsize XXIV Parts by dry weight Emulsion polymer of 90% methyl acrylate and 10% acrylic acid 100` Durez 14798 7 Aerosol 18 (disodiurn N-octadecyl sulfosuccinimate) (35% solids) 5 Backsize XX V Parts by dry Weight Emulsion polymer of 95% vinyl acetate, 5% maleic anhydride 100 Dure-z 14798 15 Igepon T-43 (sodium N-methyl-N-oleoyl taurate) (33% solids) 7 Backsl'ze XXVI Parts by dry weight Emulsion interpolymer of 70% butadiene, 25% acrylonitrile, itaconic acid 100 Durez 14798 Duponol C 5 Although the film-forming polymer has been referred to broadly herein as an oil-resistant, film-forming polymer, in its preferred form it is an aliphatic hydrocarbon polymer.

The Cypel and other coatings of this invention are applied by any of the standard coating techniques, as by knife coating, roller-coating, or print coating, after which the sheet is passed through a drying oven to remove solvent.

The thickness of the release coating may vary, but it is very thin, being in the neighborhood of about .O1-0.5 mil.

The normally tacky and pressure-sensitive adhesive may be any of those used in the art, examples being compositions containing an elastomeric component which is usually a natural or synthetic rubber, or similar elastomeric polymer, and a resinous component compatible with the binder and adapted to impart tack to the adhesive composition, together with suitable amounts of various types of additives, such as conventional iillers, anti-oxidants, etc.

It is believed that the new and useful results of this invention are due in large part to the use of a polymer made from a mixture containing a polymerizable unsaturated monomer, i.e., a carboxylic acid. Although I have given `examples of several release .coatings containing polymers made from several different types of carboxylic acids (acrylic acid, methacrylic acid, ethacrylic acid, maleic acid and itaconic acid), many other carboxylic acids having a double bond oc, to the carboxylic group (such as fumaric acid, aconitic acid, chloromalic acid, citraconic anhydride, or N-carbamyl maleimide, and the corresponding aci-ds and anhydrides) can be used in a similar way with similar results, in amounts of from 1 to 25% (and preferably 2 to 10%), of the oil-resistant, film-forming polymer.

r[he water-dispersible, heat-reactive aldehyde of imide resin may be present in an amount from 0.9 to 25 of the dry weight (and preferably 5 to 15%) of the backsize.

It will therefore be apparent that the release backsize coatings of this invention will anchor well to the customary base materials, will have satisfactory ink adherence, and will have easy release properties which are retained even though subjected to elevated temperatures. Furthermore, they do not impair the tackiness of the pressure-Sensitive adhesive coating.

Although I have hereinbefore referred to pressure-sensitive adhesive tapes, it will be understood that this invention is not limited to tapes, but may be applied to labels or any materials having a layer of pressure-sensitive adhesive in contact with the release side of an interliner, or my release coating may be applied to both sides of a liner adapted to be inserted between adjacent layers of pressure-sensitive adhesive tape or other material that has been coated with adhesive on both sides.

In the accompanying drawing, the FIGURE is a fragmental perspective view of a tape embodying the present invention. In this figure 11 is a backing, 12 is a pressuresensitive adhesive applied to one side of the backing, and 13 is an aqueous mixture of an aldehyde or imide resin, a sulfated or sulfonated wetting agent containing an 11-21 carbon atom aliphatic straight chain, and a polymeric reaction product of Inonoene or diene monomer and a monomeric polymerizable carboxylic acid with a double bond a, to the carboxylic group.

It is apparent that many widely different embodiments of this invention may be made without departing from the spirit and scope thereof; and, therefore, it is not intended to be limited except as indicated in the appended claims.

I claim:

l. A pressure-sensitive adhesive tape containing a ilexible backing which has a pressure-sensitive adhesive on one side, and on the opposite side a thin release coating comprising a film-former consisting essentially of (l) a water-dispersible, heat-reactive resin of the group consisting of aldehyde and imide resins;

(2) an emulsifying agent consisting essentially of a sulfated or sulfonated wetting agent containing at least one aliphatic straight chain of 11-21 carbon atoms; and

(3) an oil resistant, nlm-forming interpolymer derived from a polymeric reaction product of a member of the group consisting of monoene monomers, diene monomers, and mixtures of these, and a monomeric polymerizable carboxylic acid with a double bond to the carboxylic group, said monomeric polymerizable carboxylic acid being present in an amount of from l to 25% of said film-forming interpolyrner;

said water-dispersible, heat-reactive resin being present in the mixture in from about l to 33 parts by weight based on 99 parts by weight of said hlm-forming interpolymer.

2. rthe pressure-sensitive adhesive tape of claim l, in which the components of the interpolymer are ethyl acrylate, acrylonitrile and an acrylic acid.

3. The pressure-sensitive adhesive tape of claim 1, in which the interpolymer of the release coating is ethyl acrylate, acrylonitrile and an acrylic acid present in the proportions of about 6i), 35 and 5, respectively.

4. The pressure-sensitive adhesive tape of claim l,

17 in which the emulsifying agent is sodium lauryl sulfate.

5. The pressure-sensitive adhesive tape of claim 1, in which the aldehyde is a Water-dispersible, heat-reactive phenol-formaldehyde.

6. The pressure-sensitive adhesive tape of claim 1, in which the aldehyde is a water-dispersible, heat-reactive urea-formaldehyde.

7. The pressure-sensitive adhesive tape of claim 1, in which the aldehyde is a Water-dispersible, heat-reactive me1amine-formaldehyde- 8. The pressure-sensitive adhesive tape of claim 1, in which the carboxylic acid is methacrylic acid.

13 9. The pressure-sensitive adhesive tape of claim 1, in which the components of the interpolymer are butadiene, acrylonitrile and acrylic acid.

References Cied in the le of this patent UNITED STATES PATENTS 2,548,980 Kellgren Apr. 17, 1951 2,607,711 Hendricks Aug. 19, 1952 2,725,981 Abere et al Dec. 6, 1955 2,787,603 Sanders Apr. 2, 1957 2,791,519 Gerke etal May 7, 1957 2,923,646 Jordan Feb. 2, 1960 

1. A DYESTUFF WHICH IS ONE OF ITS TAUTOMERIC FORMS
 1. A PRESSURE-SENSITIVE ADHESIVE TAPE CONTAINING A FLEXIS OF THE FORMULA: IBLE BACKING WHICH HAS A PRESSURE-SENSITIVE ADHESIVE ON
 7. A POLY-ACRYLO-NITRILE FIBER DYED WITH A DYESTUFF THE GROUP CONSISTING OF MONOENE MONOMERS, DIENE WHICH IN ONE OF ITS TAUTOMERIC FORMS IS OF THE FORMULA: MONOMERS, AND MIXTURES OF THESE, AND A MONOMERIC 